1. Field of the Invention
The invention relates to a connecting element for a first and a second conduit segment, particularly for connecting a flue gas inlet of a gas turbine to a flue gas conduit discharging into a waste heat boiler, wherein the first conduit segment is insulated on the outside and has a supporting or load-bearing inner casing, the second conduit segment is insulated on the inside and has a supporting or load-bearing outer casing being offset radially outwardly from the supporting inner casing of the first conduit segment, and the supporting casings are each constructed in flange-like fashion and are form-lockingly joined together in a connection region between the two conduit segments. A form-locking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements.
When a gas turbine outlet is joined through an externally insulated metal compensator to an internally insulated diffusor of a flue gas conduit that discharges into a waste heat boiler of a gas and steam turbine system, the supporting outer casing of the internally insulated conduit segment (diffusor) is offset radially outwardly by the thickness of the insulation at the connecting point relative to the supporting inner casing of the externally insulated conduit segment (metal compensator).
When an operationally dictated thermal expansion of the supporting inner casing of the externally insulated conduit segment occurs, the connecting point, which is flue gas-tight and which is formed by a flange-like construction of the supporting casings, is strained and deforms from bending because of the force occurring in the thermal expansion that acts like a lever. The danger then exists that the thin-walled flange-like ends of the supporting casings will be impermissibly deformed or strained.